I
try to do “alter system register” and try multiple things. But nothing work out
for me.

Reason
for no service are displayed in the listener status, No service are register
with the listener. To register the service in the listener, we need to
configure local_listener,remote_listener
& listener_networks properly

Note: I am
configuring the listener_networks, because
I use a second IP or different IP for the data guard services.